a) Field of the Invention
The present invention relates to a retractable spike system devised to provide multiple spikes under the sole of a footwear and thus to make the footwear non-slippery whenever required by the user.
The invention also relates to a footwear incorporating such a retractable spike system.
b) Brief Description of the Prior Art
It is well known to provide spikes under a footwear such as a shoe or a boot to provide gripping and traction, especially under slippery conditions. Spikes, made of metal or otherwise, are efficient to prevent slipping, but become inconvenient on hard surfaces such as streets or floors.
A typical example of footwears that require spikes in certain conditions only are golf shoes. Gripping is necessary on most surfaces of a golf course; however metal spikes are damaging to the greens and a growing number of golf courses are banning them altogether. Therefore, there is a need for golf shoes with spikes that can be retracted into the soles of the shoes whenever required.
It is already known to provide the heel or sole of a footwear with retractable spikes. Reference can be made in this matter to U.S. Pat. Nos. 351,415 (WELLER); 1,361,078 (LYNN); 1,487,976 (ROSSI et al); 1,607,296 (NOEL); 2,920,404 (ROSS) and 3,343,283 (HENRY et al.). Reference can also be made to Canadian patent 2,089,221 granted to the same Applicant on Jul. 9th, 1996.
This Canadian patent 2,089,221 discloses a retractable spikes assembly insertable into a cavity made in the heel or the sole of a footwear.
The assembly comprises a bottom plate extending flush with the bottom surface of the footwear when the assembly is mounted into the cavity. A carrier plate extends parallel to the bottom plate and above it. This carrier plate has at least two integral spaced apart spikes projecting downwardly. The bottom plate is provided with guiding holes through which the lower ends of the spikes extend.
The assembly also comprises a L-shape member having a vertical arm whose lower end is rigidly attached to the carrier plate, and a horizontal arm extending from the upper end of the vertical arm. The horizontal arm has a central hole through which extends a guiding pin projecting from the bottom plate. A compression spring is mounted on the guiding pin between the bottom plate and the horizontal arm of the L-shaped member. This spring pushes the carrier plate upward when no pressure is applied on it, keeping the spikes retracted into the footwear.
The assembly further comprises a cam held pivotably above the carrier plate, having an angular position where it engages the carrier plate and therefore extends the spikes downward from the bottom surface of the footwear. The cam can be actuate from a side of the heel or sole. For example a peg can be operatively connected to the cam and have an end extending flush with the side of the heel or sole, this end having a slot that can be engaged by an edge of a coin.
This prior art assembly has several advantages. First, its mechanism operates properly even if it becomes clogged with mud. Secondly, the spikes are easy for the user to extend or retract at will. Thirdly, the appearance of the shoe is not unduly affected by this assembly, since only the slotted end of the peg is visible from the outside.
As a matter of fact, the only drawbacks of the prior art assembly described above are the limited number of spikes that can be mounted in the footwear, and the limited area of the bottom surface of the sole they can cover. One such assemblies cannot be used to provide spikes distributed on the entire bottom surface of the footwear, providing more efficient traction for the user. Moreover, even if two or more such assembly are mounted in different cavities made in the heel and sole, each assembly needs to be actuated individually, which can be tiresome for the user.
Therefore, there is a need for a system providing retractable spikes distributed on the entire bottom surface of a footwear, and where all of the spikes are actuated by a single means.